1. Field of the Invention
The present invention generally relates to the field of ramps. More particularly, the present invention relates to the field of powered assemblies for deploying or stowing a ramp in a vehicle.
2. Description of the Prior Art
Powered movable ramps are widely used for enabling persons who are physically challenged or otherwise have limited mobility to board and leave a vehicle. The following references disclosed various prior art vehicle ramps.
U.S. Pat. No. 4,131,209 issued to Manning on Dec. 26, 1978 discloses a vehicle entrance ramp. A motor bus has a side door at its forward end which when opened accommodates laterally outward extension of a ramp from a normally stowed position below the floor of the bus. A portion of the ramp adjacent the outer end serves as a step for entering the bus when the ramp is in its stowed position.
U.S. Pat. No. 4,294,571 issued to Tordella on Oct. 13, 1981 discloses a van platform with a lockable ramp. The platform includes a housing which is installed upon the floor of a van or truck. The housing includes a first floor located over the van floor to define a storage space therebelow, in which space a ramp is located. The ramp is arranged to be moved out of its retracted position in the housing space to an extended, inclined ramp-functioning position. The ramp includes rollers to facilitate movement of the ramp to the extended position. Upwardly inclined blocks are located within the housing and each includes an indentation for the reception of an associated roller as the ramp reaches a desired position adjacent the top surface of the first floor.
U.S. Pat. No. 4,850,788 issued to Dickson on Jul. 25, 1989 discloses a ramp assembly for trailers and the like. It includes a pair of parallel ramp plates reciprocably supported in tracks under the bed of a trailer. An arresting cam assembly is mounted on the rear of the trailer, and includes a control handle which is connected to and rotates a cam rod which carries and is keyed to a plurality of spaced cam plates. These cam plates are rotated with the cam rod to bring the lobes of the cam plates against the ramp plates, forcing them into a locked status against the underside of the bed of the trailer.
U.S. Pat. No. 4,979,867 issued to Best on Dec. 25, 1990 discloses a ramp which is attached to and used for the loading and unloading of goods from a vehicle. When not in use, the ramp folds compactly and is latched in an upright position at the rear of the vehicle. When in use, the ramp is unfolded and extended in order to transport goods to and from the vehicle.
U.S. Pat. No. 5,085,555 issued to Vartanian on Feb. 4, 1992 discloses a spring biased vehicle access ramp. It includes alternative horizontal and vertical pivot assemblies. A foldable ramp is pivotably attached to a horizontal axis hinge, and vertically pivotable around a vertical rod at a side of a doorway. For deployment to the ground, the ramp is pivoted horizontally and unfolded.
U.S. Pat. No. 5,160,236 issued to Redding et al. on Nov. 3, 1992 discloses a retractable van side door ramp which includes a longitudinally short base end section and a considerably longer outer end section. The ramp and the van floor include coacting guide structures for supporting and guiding the ramp during extension and retraction, but the coacting structure ceases to support and guide the other end portion of the ramp as the ramp moves to its fully extended position.
U.S. Pat. No. 5,391,041 issued to Stanbury et al. on Feb. 21, 1995 discloses a hydraulically operated bus ramp mechanism for deploying a wheelchair ramp at the door of a vehicle. The ramp rotates between a stowed position at which it is flush with the vehicle floor and a deployed position in which it slopes downwardly and outwardly from the vehicle. The ramp is rotated between stowed and extended positions by a hydraulic drive mechanism which includes motor/pump/valve unit and hydraulic cylinder. The mechanism provides a float down feature which permits the ramp to move downward under gravity without the need for operator control and prevents crushing of obstacles that get in the downward path of the ramp.
U.S. Pat. No. 5,393,192 issued to Hall et al. on Feb. 28, 1995 discloses an underfloor extendible ramp for vehicles. It includes a tray mountable under the floor of the vehicle. The tray includes an extendible ramp mechanism which has a ramp and a driving panel for the ramp. The ramp is fulcrumed intermediate its ends on the outer ends of parallel arms extending from the driving panel. A pair of toothed belts driven by a reversible rotating motor are attached to the driving panel for extending and retracting the ramp from the tray.
U.S. Pat. No. 5,676,515 issued to Haustein on Oct. 14, 1997 discloses a low floor vehicle ramp which includes a slide way attached to a bottom side of the vehicle floor proximate a door sill and a boarding-ramp assembly hinged to a ramp-control plate that slides on parallel slide ways as actuated horizontally by motorized bidirectional actuation of a ramp-slide actuator that is affixed to the vehicle and has a horizontally actuating member attached to the ramp-control plate. A floor-access plate forms an access bridge between the boarding-ramp assembly and the vehicle floor.
U.S. Pat. No. 5,813,071 issued to Breslin et al. on Sep. 29, 1998 discloses a telescoping truck loading ramp assembly for facilitating the loading and unloading of a truck. The ramp assembly includes two telescoping ramp sections each having a forward section and a rearward section movable relative to each other between a full length ramp operating configuration and a stowed configuration.
While many different vehicle ramps have been disclosed by the prior art, there remains a need to have a very efficient and also very effective design and construction of an improved flip-over ramp which can be normally stowed in a horizontal position in a recess in a vehicle floor and can also be pivoted upward and outwards to a downward sloping extended position, after the vehicle door has been opened.